Electromagnetic switch and thermally released shorting switch



Feb. 6, 1951 T. R. WELCH ELECTROMAGNETIC SWITCH AND THERMALLY RELEASEDSHORTING SWITCH Original Filed Deo. 28, 1945 e5 79 se a@ 43 IN1/EwenTHOMAS Ross WELCH HIJ' ATTORNEY Patcnted Feb., 6, 1951 ELECTROMAGNETICSWITCH AND THER- MALLY RELEASED .SHORTIN G SWITCH Thomas Ross Welch, LosAngeles, Calif.

Original application December 28, 1945, Serial No.

637,711, now Patent No. 2,490,182, dated December 6, 1949. Divided andthis application March 13, 1947, Serial No. 734,448

(Cl. 20o-88 1a claims. l

My invention relates to a new and useful electromagnetic switch andthermally released shorting switch, of which the following specificationis a division of my co-pending application Serial No. 637,711, filedDecember 28, 1945, now Patent No. 2,490,182, December 6, 1949, entitledElectric Sign.

This invention relates to a circuit controlling device and particularlyto a control device of the type in which a low voltage circuit isemployed to actuate the switching mechanism of a high voltage circuit.

The present invention, as well as that set forth in Patent No. 2,490,182is particularly directed to an invention for use with an electric sign,such as setout in Letters Patent of the United States, Number 2,290,261granted to me July 21, 1942.

It is the general object of the present invention to provide anelectromagnetically actuated switch mechanism adapted to be operated ina novel manner, making it possible to control a high voltage circuitinvresponse to the energization of a low Voltage circuit.

A further object of my invention is to provide a simple switch mechanismwherein the high voltage terminals are spaced suiliciently that thedanger of high voltage arcing is minimized.

A further object of my invention is to provide a switching mechanism,including a hollow body of insulating material, having a dividing wallso as to form isolated chambers, one to contain an electromagnet withthe poles thereof in close proximity to one side of the dividing Walland a switch mechanism having an armature in close proximity to theother side of the dividing wall so that upon energization of theelectromagnet, the armature will be caused to move whereby the switchmechanism is actuated.

A further object of my invention is to provide a simple electromagneticswitch mechanism having spaced terminals for connection to a highvoltage circuit with a simple safety means for operation between theterminals when excessive high potentials are encountered which mayotherwise injure the contacts of the switch mechanism.

These and other objects of the invention will become apparent in thespecification with reference to the accompanying drawings thatillustrate preferred embodiments thereof, in which Fig. 1 is alongitudinal sectional view of one embodiment of my invention.

Fig. 2 is a view oi the left end of Fig. 1 with the cover removed.

Fig. 3 is a longitudinal sectional view of another form of my invention.

Fig. 4 is a longitudinal sectional view o1' still another form of myinvention.

In Fig. 1 I have shown a circuit control device I0 comprising a shellhaving a tubular wall I I of insulating materia] supporting a transversewall I2 disposed intermediate the ends of the wall II so that twochambers I3 and I4 are formed in the shell. The shell may be molded orotherwise formed from a suitable insulating material with one endthereof provided with a radial flange I 5. 'I'he one chamber I4 is shownas having a greater axial length than the other chamber I3 and receivesan electromagnet I6. The electromagnet I6 comprises a core I'I with endpieces I8 and I9 forming a spool to carry a winding 20.

Positioned at the rear end of the core I1 a flat metal fleld piece 2| issecured, this leld piece 2l being bent so as to lie along one side ofthe electromagnet and is provided with a magnetic pole 22 adjacent thepole 23 formed by the front so as to cover the rear end of theelectromagnet I 6. The poles 22 and 23 of the electromagnet I6preferably rest in depressions 29 and 30 formed in the transverse wallI2 facing the chamber I4.

'I'he chamber I3 of the control device I0 contains a magneticallyactuated switch mechanism 3| comprising an armature 32 which may be arectangular piece of fiat soft iron disposed in spaced relation to thetransverse wall I2 and so positioned that when the electromagnet I6 isenergized through the leads 20', the magnetic flux will attract thearmature 32 towards the poles 22 and 23 and against the transverse wallI2. The armature 32 is supported by a resilient member 33 preferablymade from a fiat strip of hard brass or bronze, bent to a Z-shaped form,so that one end 34 thereof will lie across the outer face of the ange I5and its inner end 35 will project into the chamber I3 and secured as bymeans of rivets 36 to the armature 32. The free end 3l of the armature32 has a contact 4I mounted thereon to cooperate with a contact member42, which is supported on a supporting member 38 formed from a flatstrip of conducting metal, bent to a reverse Z-shaped form so that oneend 39 thereof will lie across the outer face of the flange I5, in aposition substantially diametrically opposite to the outer portion 34 ofthe member 33, and the inner end of the supporting member 38wil1 projectinto the. chamber I3 for cooperation with the armature 32.`

As shown in Fig. 1 the support member 33 normally holds the armature 32in a position that the contact member 4| on the armature 32 will be heldwith pressure against the contact member 42 on the support member 38.When the electromagnet I6 is energized the armature 32 will be movedto'ward the transverse wall I2 to carry the contacts 4| and 42 out ofengagement with one another. The actuation of the switch 3| lmay beconsidered either the closing movement or the opening movement or bothas it may be desired.

` The control switch I8 is provided with a safety device to bridgethrough the actuated switch v3| if the contacts 4| and 42 should beburned out resulting from arcing by excessive current passing throughthe leads 43 and 44. This safety device 45 as shown in Fig. 1, comprisesa spring member 45 having one end 48 connected y with the contact member38 against the iiange I5 and bowed so that its free end 41 may be heldby a fuse element 48 in a recess 49 provided on the end portion 40 ofthe support 38. 'I'he operation of the safety device ls as follows, ifexcessive current is temporarily passed through the leads 43 and 44 toburn out the contacts 4| and 42 the heat generated by the arcing issufficient to melt the fuse element 48 allowing the free end 41 of thespring element 45' to move into contact with the member 33 thus bridgingthe section between and thereby closing the circuit from terminal 50 toterminal 5| and restoring the circuit to an operating condition.

The terminals 50 and 5| besides serving as connectors for the leads 43and 44 also serve as fastening means for securing the spring member 45and support member 38 and the support member 33 of the switch mechanism3l to the face of the flange I5. The terminals 5@ and 5I comprise screwmeans 52 having a head or nut 53 in-1 termediate the ends thereof, tobear against the end portions 39 and 45, and 34, to clamp such endportions against the face of the fiange member I5 when nuts 54 areapplied to the ends of the screw means 52 which project through openings55 in the flange I5. The terminals 5@ and 5I also serve as fasteningmeans for a cover or seal 5t that may enclose the switch mechanism iii,by mounting the cover 55 on the outer portion 58 of the screw means 52through the openings 51 and securing the cover in place by nuts 5t)applied to the ends of the screw means 52. may have a cylindrical lip t@to extend around the edge of the face of the flange member I5.

In Fig. 2 I have shown a View of the right end of Fig. '1 with the coverremoved showing the rel-s ative positions of the switching mechanismparts and the method of securing the members in their respectivepositions.

In Fig. 3 I have shown an alternative form of my control device with thecover removed. The use of a cover being optional. This form issubstantially the same as that shown in Fig. l, with the variation inthe switching mechanism 3i'. In this form of my invention themagnetically operated switch 3 I comprises a rigid fiat conductive metalsupport member 6I bent to an L-shaped form so that one end 62 will lieacross the outer face of the flange member I5 and the other end portion63 will project into the chamber I3. The end portion 63 has a cut outsection to provide an opening 64 for the reception of an armature 65 Thecover 5t l.

which is held in place against the support member 8| by a coil spring 88which has one end connected to a clip 61 formed on the support member 8|and its other end connected to a clip 88 formed on the amature 65. Thefree end of the armature 85 is held with pressure against a stationarycontact member 33 positioned diametrically opposite the member 62. Thesafety device means 45 Is mounted similarly to that shown in Fig. 1.

In Fig. 4 I have shown an alternative form of my control deviceeliminating the use of two chambers in the shell, the lshell comprisinga tubular wall 10 and a transverse wall 1| cooperatlng to form a singlechamber 12 to receive the electromagnet 16. The pole pieces 22 and 23'extend into cavities or recesses 13 and 14 respectively in thetransverse wall 1| facing the chamber 12, thereby providing a thin wallsection in the wall 1| adjacent the end of the pole pieces 22 and 23.

In this form of my invention the flange 13 of the shell 69 liessubstantially in the same plane as the transverse wall 1| and themagnetically operated switch 15 may be disposed in a chamber 18 formedwithin a cover 11 of cup-shaped form which is secured to the outer faceof the flange 13 by screw means 19.

The magnetically operated switch 15 comprises a rigid fiat conductivemetal support member having one portion 8| secured to the outer face ofthe flange member 13 by means of one of the screw means 19. The free endof the support member 80 is bent outward and inward to formsubstantially a U portion 82 the end of which lies adjacent to thetransverse wall 1I. The end portion of the support member 80 has a cutout section to provide an opening 83 for the reception of an armature 84which is held in place against the support member 80 by a coil spring 93which has one end connected to a clip 94 formed on the armature 84 andits other end connected to a clip 35 formed on the support member 88.The armature 84 is disposed adjacent the wall 1I for movement towardsthe pole pieces 22' and 23 when the electromagnet 'It is energized butis normally in contact with a stationary contact member 85 biased by thecoil spring 83.

The stationary contact member 85 comprises a rigid fiat conductive metalsupport member 85 bent to substantially a Z-shaped form and having oneportion 88 secured to the flange member 13 by means of one of the screwmeans 13, diametrically opposite to the outer portion 8i of the supportmeans 88. The other end 86 of the support means 85 extends parallel tothe transverse wall 1I but spaced therefrom so as to cooperate with thearmature 84.

A safety device 88 is provided to bridge the actuated switch 15 for thehigh voltage current if the contacts of the switching mechanism areburned out by excessive high current passing through the leads 43 and44. This safety device 88 is shown to comprise of a spring member 88having one end portion 89 seated on the flange member 13 and held inplace by screw means 19. The free end 90 of the spring member 88 isbowed and held by a fuse member 9| in a recess 92 formed in the endportion 81 of the support member 85. Excessive current passing throughthe leads 43 and 44 that is sufficient to burn out the contacts, willgenerate suiiicient heat to melt the fuse element 9| so as to allow thefree end 9 0 of the spring member 88 to move into contact with theamature 84 to close a circuit between the leads 43 and 44. Y

The screw means 19 besides serving as a iastening means for switch partsby retaining them against the face of the flange 13 also serve asterminals for the leads 43 and 44 and as a fastening means for the cover11 against the face of the flange 13. y

From the foregoing description and the several forms illustrated it willbe seen that I have provided an elcctromagnetically actuated switchmechanism which may be economically manufactured, is efiicient anddurable in operation and cam-able of modification and rearrangementwithout departing from the spirit and scope thereof.

I claim as my invention:

1. In a switch device of thecharacter de-l scribed: a tubular shell ofinsulating material, said shell having a transverse wall of insulatingmaterial intermediate its ends which forms an insulating barrier in saidshell so as to form in said shell an inner chamber and an outer chamber;an electromagnet disposed in said inner chamber adjacent said transversewall; an armature in said outer chamber adjacent said transverse wall,said armature being readily movable in response to the magnetic flux ofsaid electromagnetj a strip of metal suitably mounted in said outerchamber to movably support said armature and conduct electrical energythereto; a switch contact member suitably mounted in said outer chamberand positioned to be engaged by said armature when said armature is inone of its operative positions; a flexible member having one end thereofpermanently associated with said switch contact and having its free endheld against said switch contact by a fuse element and said free endbeing adapted when released by said fuse element to move into engagementwith said strip of metal; a cover for said outer chamber; means forconnecting conductors to said metal strip and said switch contact; andmeans for connecting the inner end of said tubular shell to a support.

2. In a switch device of the character described, 'the combination of: ahollow shell of insulating material, said 'shell having .a barrier ofinsulating material intermediate its ends so as to form in said shell aninner chamber and an outer chamber; an electromagnet disposed in saidinner chamber adjacent said barrier; an armature in said outer chamberadjacent said barrier, said armature being adapted to be moved by saidelectromagnet; a strip of metal suitably mounted in said outer chamberto movably support said'armature and conduct electric energy thereto; aswitch contact member suitably mounted in said outer chamberdiametrically opposite said strip of metal and formed to be engaged bysaid armature when said armature is in one of its operative positions; aflexible metal strip having one end thereof xed to said switch contactand having its free end held against said switch contact by a fuseelement, said free end being adapted when released by said fuse elementto move into engagement with said strip of metal; and means forconnecting conductors to said metal strip and saidswitch contact.

3. In a switch device of the character described, the combination of atubular shell of insulating material, said shell having a. transversebarrier of insulating material intermediate its ends so as to form aninner chamber and an outer chamber; an electromagnet disposed in saidinner chamber adjacent said transverse barrier;

an amature in said outer chamber adjacent said transverse barrier, saidarmatre being adapted to be moved by said electromagnet; a metalstripsuitably mounted in said cuter chamber being adapted to movably supportsaid armature and conduct electric energy thereto; a switch contactmember suitably mounted in said outer chamber diametrically oppositesaid metal strip and formed so as to be engaged by said armature whensaid armature is in one of its operative positions; a flexible metalcontact having one end secured to said switch contact and formed in abow by holding its free end in engagement with said switch contact bymeans of a fuse element, said free end being adapted to movesufficiently far to engage said metal strip when released by said fuseelement for closing the gap between said switch contact and said metalstrip if said switch contact is burned out by high voltage current; andmeans for connecting conductors to said switch contact and said metalstrip.

4. In a switch device of the character described: a tubular shell ofinsulating material having a barrier of insulating material intermediateits ends so as to form in said shell an inner chamber and an outerchamber, said shell having adjacent the outer chamber a radiallyextending ange; an electromagnet disposed in saidinner chamber adjacentsaid barrier; an armature in said outer chamber adjacent said barrier,said armature comprising an electro-.conductive material; a strip ofmetal extending from said flange into said outer chamber to'movablysupport said armature and conduct electrical energy thereto; and astationary switch contact member extending from said flange into saidouter chamber to a position whereby said contact member will be engagedby said armature when the latter is in one of its operative positions.

5. In a switch device of the character described, the combination: atubular shell of insulating material having a transverse barrier ofinsulating material adjacent one end thereof to form a chamber withinthe shell, said shell having a radially extending flange adjacent theouter end thereof; an electromagnet disposed in said chambe1` on oneside of said transverse barrier; an armature adjacent the other side ofsaid transverse barrier; a support member connected to said flange andmovably supporting said armature; a stationary switch contact elementsupported on said ange in spaced relation to said support member andpositioned whereby said contact element and said armature will be inengagement when said armature is in one of its operative positions;spring means biased between said support member and said armaturewhereby pressure is exerted against said stationary contact element; andmeans for connecting conductors to said support member and said contactelement.

6. In a switch device of the character described: a hollow casing ofinsulating material having a radial flange adjacent one end thereof,said housing having a barrier therein of insulating material so as toform a chamber therein; an electromagnet disposed in said chamberadjacent one face of said barrier; an armature disposed adjacent theother face of said barrier, said armature comprising anelectro-conductive material; a metal support extending from said flangeto said barrier to movably support said armature and conduct electricalenergy thereto; a switch contact element extending from said flange inspaced relation to said metal support and laying across said barrier butspaced therefrom whereby it engages said armature whensaid armature isin one of its operative positions; and a spring biasing said armaturewhereby pressure is ex'erted by said armature against said contactelement.

7. In a switch device of the character described, the combination of: atubular shellof insulating material having a transverse barrier ofinsulating material intermediate its ends so as to form in said shell aninner chamber and an outer chamber, and having an outward extendingradial flange at the outer end thereof; an electromagnet disposed insaid inner chamber adjacent said transverse barrier; an armature in saidouter chamber adjacent said transverse barrier, said armature comprisingan electro-conductive material; -a strip of metal forming a supportfor-said armature, said strip of metal having an outer portionoverlaying the outer face of said flange; a switch contact memberoverlaying the outer face of said flange and diametrically oppnsite tosaid strip of metal, and extending into said outer chamber to a positionfor'engagement with said armature when said armature is in one of itsoperative positions; fastening means extending through said fiange andthrough said strip of metal and said contact member whereby said stripof metal andccntact member are retained on said ange; and conductormeans connected to said fastening means.

8. In a switch device of the character described, the combination of: atubular shell of insulating material having a transverse barrier wall ofinsulating material intermediate its ends so as to form in said shell aninner chamber and an outer chamber, and having an outwardly extendingradial flange formed at the outer end thereof; an electromagnet disposedin said inner chamber adjacent said transverse wall; an armature in saidouter chamber adjacent said transverse wall, said armature comprising anelectroconductive material; a strip of metal forming a support for saidarmature, said strip of metal having a portion overlaying the outer faceof said ange; a switch contact member in spaced relation to said stripof metal and having an outer portion overlaying the outer face of saidflange, and extending into said outer chamber to a position forengagement lwith said armature when said armature is in one of itsoperative positions; a cover overlaying the outer face of said flange soas to close said outer chamber; and fastening means through said flangeand said cover for retaining said strip of metal and said contact meansin position and serving as an attachment for conductor means.

9. In a switch device of the character described, the combination of: atubular shell having a transverse electrically insulating barrier and anoutwardly projecting radial flange, there being a chamber in said shelladjacent the inner face of said transverse barrier; an electromagnet insaid chamber adjacent said inner face of said transverse barrier; anarmature lying adjacent the outer face of said transverse barrier inposition to be attracted when said electromagnet is energized; a springelement for supporting said armature in spaced relation to the outerface of said transverse barrier, the outer end of said spring elementextending across the outer face of said liange; a movable contactcarried by said armature; and a stationary contact element positioned soas to be engaged by said movable contact, said stationary contactelement having an outer portion extending across the outer face of saidiiangein spaced relation to the outer portion of said spring element.

l0. In a switch device of the character described, the combination of: atubular shell having an outward projecting radial ange and a transversewall providing an electrical barrier and forming a chamber in said shelladjacent one face of said transverse wall; an armature lying adjacentthe other face of said transverse wall in a position to be attractedwhen saidelectromagnet is energized; a spring element for supportingsaid armature in spaced relation to the face of said transverse wall,the outer portion of said spring element extending across the outer faceof said ange; a movable contact carried by said armature; a stationarycontact element positioned so as to be engaged by said movable contact,said stationary contact element having a portion extending across theouter face of said iiange in spaced relation to the outer portion ofsaid spring element; screwmeans for securing said spring element andsaid stationary Contact element to said iiange and whereby connectionmay be made by conductors to said spring element and said stationarycontact element; and a cover overlaying the outer face of said flange soas to conceal said armature and held in place by said screw means.

11. In a switch device of the character described, the combination of: atransverse wall of insulating material; an electromagnet disposedadjacent one side of said transverse wall; a movable armatureoperatively disposed adjacent the other side of said transverse wallwhereby said armature may be operated by said electromagnet when saidelectromagnet is energized; primary switch means associated with saidarmature so asand the other end being releasably held to said primaryswitch means by a fuse element in heat exchange relation with thecontacts of said primary switch means and being adapted, upon release bysaid fuse element, to bridge said primary switch contacts when saidprimary switch means encounters high potentials sufn'cient to injuresaid primary switch means.

12. In a switch device of the character described: a transverse wall ofinsulating material; an electromagnet disposed adjacent one side of saidtransverse wall; a movable armature operably disposed adjacent the otherside of said transverse wall whereby said armature may be operated bysaid electromagnet when the latter is energized; primary switch meansassociated with said armature so as to be actuated thereby, said primaryswitch means includingswitch contacts; means vfor connecting electricalconductors to said primary switch means; and secondary switch meanshaving two end portions, one end portion being xed and the other endportion being releasably held by a fuse element in heat exchangerelationship with the primary switch contacts, said secondary switchmeans bridging the primary switch contacts upon release by said fuseelement.

13. In a switch device of the character described: a transverse wall ofinsulating material; an electromagnet disposed adjacent one side of 9said transverse wall; a movable armature operably disposed adjacent theother side of said transverse wall whereby said armature may be operatedby said electromagnet when the latter is energized; primary switch meansassociated with said armature so as to be actuated thereby, said primaryswitch means including switch contacts; means for operably connectinghigh voltage conductors to said primary switch means; secondary switchmeans having end portions, one ol' said end portions being fixed; and afuse element in heat exchange relation to the primary switch contacts,said fuse element releasably holding the other end portion of saidsecondary switch means in an open position, said secondary switch means,upon release by said fuse element, bridging the primary switch contacts.

THOMAS ROSS WELCH.

10 REFERENCES CITED '.L'ne following references are of record in the leof this patent:

UNITED STATES PATENTS

